As one of the most promising cathode materials for next-generation of lithium-ion batteries, Li-rich Mn-based oxides are still hindered by inferior cycling properties and poor rate performance. Surface modification is proved to be feasible to tackle these problems. Herein, we chose phytic acid to construct spinel and Li3PO4 double protection layers on the Li1.2(Ni0.17Co0.07Mn0.56)O2 cathode material via a simple synchronous approach. The 3 wt% phytic acid treated sample achieves markedly enhanced electrochemical performance, such as elevated initial Coulombic efficiency reaching 90.0%, increased capacity retention of 87.8% after 150 cycles at 1 C and alleviated average discharge voltage drop of 1.63 mV per cycle. These impressive electrochemical properties can be ascribed to the designed hierarchical interface, which not only can synergistically retain structural stability but also provide fast Li+ transport channels. Taken together, this work employs a facile and novel route to enhance the electrochemical performance of Li1.2(Ni0.17Co0.07Mn0.56)O2, which may afford inspiration to the commercialization of Li-rich cathode materials.